I had an idea about displaying coloured PB's whilst driving online. example:

outside 3% pb remains standard white (as it is now)
within 3% of WR your pb comes up in Blue
within 1% of WR your pb comes up in Red

Wouldn't take much to implement & it gives a rough guide of your pace.

Wouldn't make much difference for me, Although you should suggest a different color than blue. It's very tough to read against the sky.

Maybe green then but speech is in green so thats a no go.